<template>
  <div class="star star-24" :class="'star-'+size">
      <span class="star-item on" v-for="(sc, index) in starClasses" :class="sc" :key="index"></span>
      <!-- <span class="star-item on"></span>
      <span class="star-item on"></span>
      <span class="star-item half"></span>
      <span class="star-item off"></span> -->
  </div>
</template>

<script>
// 类名常量
const CLASS_ON = 'on'
const CLASS_HALF = 'half'
const CLASS_OFF = 'off'

export default {
  name: 'Star',
  props: {
    score: Number,
    size: Number
  },
  computed: {
    // 3.2: 3 + 0 + 2   3.5: 3 + 1 + 1
    starClasses () {
      const { score } = this
      const scs = []
      // 向scs中添加n个CLASS_ON
      const scoreInteger = Math.floor(score)
      for (let i = 0; i < scoreInteger; i++) {
        scs.push(CLASS_ON)
      }
      // 向scs中添加0/1个CLASS_HALF
      if (score * 10 - scoreInteger * 10 >= 5) {
        scs.push(CLASS_HALF)
      }
      // 向scs中添加n个CLASS_OFF
      while (scs.length < 5) {
        scs.push(CLASS_OFF)
      }
      return scs
    }
  }
}
</script>

<style lang="stylus" type="stylesheet/stylus" scoped>
    @import '../../common/stylus/mixins.styl'
    .star //2x图 3x图
        float left
        font-size 0
        .star-item
            display inline-block
            background-repeat no-repeat
        &.star-48
            .star-item
                width 20px
                height 20px
                margin-right 22px
                background-size 20px 20px
                &:last-child
                    margin-right: 0
                &.on
                    bg-image('./images/star48_on')
                &.half
                    bg-image('./images/star48_half')
                &.off
                    bg-image('./images/star48_off')
        &.star-36
            .star-item
                width 15px
                height 15px
                margin-right 6px
                background-size 15px 15px
                &:last-child
                    margin-right 0
                &.on
                    bg-image('./images/star36_on')
                &.half
                    bg-image('./images/star36_half')
                &.off
                    bg-image('./images/star36_off')
        &.star-24
            .star-item
                width 10px
                height 10px
                margin-right 3px
                background-size 10px 10px
                &:last-child
                    margin-right 0
                &.on
                    bg-image('./images/star24_on')
                &.half
                    bg-image('./images/star24_half')
                &.off
                    bg-image('./images/star24_off')
</style>
